Nowadays, people pay much attention to air quality in the environment. For example, it is important to monitor carbon monoxide, carbon dioxide, volatile organic compounds (VOC), fine suspended particle (PM2.5), and so on. The exposure of these substances in the environment will cause human health problems or even harm the life. Therefore, it is important for every country to develop and implement the environmental monitoring technology.
As known, portable electronic devices are widely used and applied in the modern life. In other words, it is feasible to use the portable electronic device to monitor the ambient air. If the portable electronic device is capable of immediately providing people with the monitored information relating to the environment for caution, it may help people escape or prevent from the injuries and influence on human health caused by the exposure of these substances in the environment. In other words, the portable electronic device is suitably used for monitoring the ambient air in the environment.
Although it is obviously beneficial to make the portable electronic device equipped with sensor for collecting environment data, however, when the sensor is integrated into the electronic device, the monitoring sensitivity and the precision of the sensor should be taken into consideration. For example, the sensor is in contact with the fluid circulating from the outside and transferred by naturally occurring convection in the surroundings. In other words, the sensor fails to fetch a consistent flow to maintain stably monitoring. Since it is difficult to trigger response action of the sensor by the circulating fluid transferred by convection, the response time of the sensor is long and becomes a great factor affecting real-time monitoring.
Therefore, there is a need of providing a technology of increasing the monitoring accuracy of the sensor and decreasing the response time of the sensor.